Looking Up: Autumn’s stars are in view

The autumnal equinox was this past week, when at long last, we start having more night than daytime.

Peter Becker

The autumnal equinox was this past week, when at long last, we start having more night than daytime.

I understand. Most people miss longer days, and in fact I do as well as winter time approaches. For anyone who enjoys the night sky, however, there is somewhat of a conflict. As much the long period of summer daylight is wonderful, in early summer one has to wait long - after 10 p.m. - to see a dark sky full of stars. At last, more people will be able to get outside during the mid to early evening to welcome the first stars of the night.

The arrival of autumn brings another host of seasonal evening stars that are dominating the eastern sky and each night takes over more and more of our attention as summer’s stars slip away into the west.

Autumn’s constellations are for the most part faint but hold a bounty of interest no less than a cornucopia of harvest’s blessings. Among those stars, you can find the great Andromeda Galaxy with eyes alone (in a dark, moonless sky), and with a small telescope you can track down glorious globular clusters, the star packed haze of the distant Milky Way Band and colorful double stars.

In mid-October, a strong meteor shower known as the Orionids sends bright streaks across the fall heavens. This year, brilliant planet Jupiter prevails like a champion reigning in the southern sky.

A few of the fall constellations are pictured as aquatic creatures, including Delphinus the Dolphin, Cetus the Whale, Pisces the Fish and Pisces Austrinus the Southern Fish. Joining them are Sculptor, Pegasus the Flying Horse, Andromeda and her boyfriend Perseus, Triangulum the Triangle, Aries the Ram, Aquarius the Fellow Carrying a Pitcher of Water, Lacerta the Lizard, and taking its turn riding high in the north over the North Star, Cepheus the King and his Better Half, Queen Cassiopeia.

There is only one very bright star among the autumn evening constellations, lovely blue-white Fomalhaut, the “eye” star of the Southern Fish, seen quite low in the southeast on a late September evening. Fomalhaut, which is known to be encircled by a broad, dusty disc, recently received another very unique distinction. The first exo-planet (a planet in another solar system beyond our own) ever to be directly photographed, was found in orbit around Fomalhaut. It appears to us as a minute point of light, between the disc’s dusty bands.

Interestingly, these constellations did not always mark the arrival of fall. Thanks to the “Precession of the Equinoxes,” millennia ago, whole other regions of the night sky took turns as autumn’s stars.

Autumn and spring equinox occur when the sun, on its apparent path around the sky- the path known as the ecliptic - intersects with the celestial equator. The latter is that band of sky you would see from due east to overhead to due west, if you were at the Earth’s equator. Because the Earth is tilted on its axis, the ecliptic line - where we see the sun as we go around it - is likewise tilted in respect to the celestial equator.

The Earth’s axis, which points very close to the North Star, very gradually is moving in a circle, inscribing an imaginary circle on the sky once around every 26,000 years (as I said, “very”). In other words, our world wobbles like a spinning top. This in turn means the points (the Equinoxes) where the ecliptic and celestial equator cross, ever so slowly change. Eventually, the equinoxes travel all around the sky, and one day, your descendants will see what we currently call spring stars marking the arrival of fall (or vice-versa).

Or you can forget all that and just look up and enjoy the view.

Full moon is on Oct. 4 and is known as Harvest Moon.

Comments and questions may be sent to the writer at pbecker@wayneindependent.com.